Aerojet Rocketdyne

By working closely with the MTI team and the refurbishing of the VRFW, Aerojet Rocketdyne and the RS-25 program achieved a greater than 50% reduction in cost and schedule for this process."

Mohamed ElnaggarS-25 Powerhead Team Leader

With a cost savings of $1 million and the lead time cut in half, Aerojet Rocketdyne and MTI agreed that refurbishing and upgrading the Vertical Rotary Friction Welding (VRFW) machine originally built in 1981 would be the most cost-efficient and time-saving option to develop a next generation rocket engine for NASA. MTI handled all of the upgrades for the VRFW under an extremely tight schedule and close coordination.

The Space Program Comes Back to South Bend

Since 1926, Manufacturing Technology, Inc. (MTI) has brought custom-engineered joining solutions to various industries including aerospace and military. As a leader in friction welding, MTI is the only company in the world to offer a diversity of all friction welding capabilities including rotary, linear, and friction stir welding. With over 800 MTI welding machines in operation today, the Company understands that each challenge might have its own unique solution, always making innovation a top priority.

To Boldly Go…
Aerojet Rocketdyne (AR), a leader in the development and manufacturing of aerospace propulsion systems, secured a contract with NASA to develop a next generation rocket engine to be used in deep space exploration. With decades of experience in developing cutting-edge rocket engines – including the Saturn V and Space Shuttle programs – AR now was tasked with developing a cryogenic liquid hydrogen- and liquid oxygen-propelled rocket booster engine for NASA’s Space Launch System (SLS).

The SLS program – along with the RS-25 engine being developed by AR – is scheduled to initially operate in cis-lunar space supporting what NASA calls the “proving ground” where we evaluate ways to operate independent of Earth supporting eventual missions to Mars in the early 2030s. The SLS will carry both cargo and astronauts.

A Blast from the Past: The Challenge
As part of AR’s process to recertify the RS-25 engine, a special vertical rotary friction welding machine (VRFW), built by MTI in 1981, was brought out of storage. It had originally been used to friction weld the Powerhead Main Injector on the Space Shuttle Main Engine (SSME), which was used on all 135 Space Shuttle Flights. The machine, using early ‘80s technology, naturally would not meet the modern production standards necessary to accomplish AR’s goals. In order to complete the necessary friction welding operations on the current engine components, AR sought out MTI to come up with the best way to utilize the VRFW.

Discussions between MTI and AR focused on the best manner to approach the machine and critical next steps. AR had to present a plan of action to NASA on how they were going to accomplish the build goals. They faced two choices: (1) build a new machine from scratch or (2) refurbish and upgrade the existing VRFW. Building a new machine would have cost $1.6 million and taken over a year to complete, adversely affecting AR’s manufacturing schedule, not to mention NASA’s launch schedule, for the RS-25.

So, with a cost savings of $1 million and the lead time cut in half, AR and MTI agreed that refurbishing and upgrading the VRFW would be the most cost-efficient and time-saving option. MTI would handle all of the upgrades for the VRFW under an extremely tight schedule and close coordination.

The VRFW was shipped from California to MTI’s facility in South Bend, Indiana in March 2016 and the engineers and technicians got to work scoping out the best way to tackle the refurbishment. The machine needed a great deal of upgrades to its drives, control system, software, and mechanical systems. Part of the upgrades included updating the control systems to a closed-loop process as well as more modern data manipulation using advanced computer operating systems. One minor, but challenging aspect of the refurbishing was that the component diagram hardcopies from the early 1980s were difficult to read. This necessitated scanning documents into an easy-to-use electronic format.

SUCCESS AND SETTING RECORDS: THE SOLUTIONAfter having the VRFW for only 22 weeks, MTI was able to complete the refurbishment and by September 2016 the testing commenced. This quick turnaround saved AR vital time and money. The MTI team also benefited from a close collaboration with AR and its staff – both past and present.

One of the more unique aspects of this operation, was the need to “recall” a retired Rocketdyne engineer, Earl Noteboom, to assist with the refurbishing of the VRFW. Noteboom was certified to handle the welds and parts on the RS-25 engine, and was dispatched to MTI’s South Bend facility to assist with developing the weld schedule and test the VRFW. This also helped facilitate some hands-on teaching of AR’s current generation of engineers.

MTI has a long history within the aerospace industry. However, this particular project is special – to tell the history of this machine and its role in our nation’s space program, it is amazing to have had played a part in moving from the space shuttle to the journey to Mars.

Dan Adams, MTI Chief Technology Officer

Once the test welding began, the efficiencies built into MTI’s refurbishment and upgrades of the machine became evident: 115 samples were welded in the first day, a record. This beat the initial best weld time for the VRFW. The next day the machine completed a total of 125 welds, another record. It was clear the upgrades had increased friction welding efficiencies and the machine’s abilities. During four days of operational friction welding, the VRFW – with MTI’s upgrades – made more than 600 welds that led to the completion of the necessary welds for the RS-25 booster engine – ahead of schedule.

“By working closely with the MTI team and the refurbishing of the VRFW, Aerojet Rocketdyne and the RS-25 program achieved a greater than 50% reduction in cost and schedule for this process,” said Mohamed Elnaggar, RS-25 Powerhead Team Leader. “The reductions are a credit to the efficiency of the machine and the world leading expertise at MTI.”

The Future is Now Friction welding technology is a critical method for reducing waste products, saving manufacturing time and costs, and creating a forge quality weld for similar and dissimilar metals. After the initial success of the VRFW in the 1980s, newer technologies have developed and significant advances have taken place, with equally promising success.

One important advancement in friction welding is the improved amount of data that provides better quality assurance of the welds. This leads to extremely consistent welds that are repeatable, reliable, and proven, giving the operator 100% confidence in MTI’s joining technology. With these process improvements, MTI has been able to develop different types of friction welding processes and expand them in other industries beyond aerospace such as the automotive, construction and agriculture, oil and gas, and consumer products.